Prefabricated composite building panels are well known for providing a means by which builders can quickly erect structures of high strength and having excellent thermal insulating properties. Composite panels are typically used to construct walls, ceilings and floors for factory buildings, cold rooms, agricultural growing rooms, office buildings, warehouses and portable buildings, but have many other applications.
Such composite panels typically comprise an insulating core, of polystyrene, polyurethane, polyethylene, or mineral fibre. Laminate-type composite panels have skins of steel, wood, gypsum, aluminum, plastic or the like adhered to the insulating core and are suitable for many applications. Frame-type composite panels have a frame of steel, wood or plastic affixed about the insulating core. Because the insulating core in a frame-type composite panel is not completely covered by a sheet of laminate, such a panel is better suited than its laminate-type counterpart for forming conduits for electrical systems and mounting drywall to its frame during building construction.
Frame-type composite panels may be connected to each other during building construction by affixing overlapping portions of frame members of adjacent panels using nut/bolt combinations, rivets, clips or the like.
Various methods of manufacturing frame-type composite panels are known. For example, U.S. Pat. No. 4,241,555 to Dickens et al. discloses a method of manufacturing such a panel. Dickens forms the insulating core by applying heat to a core-shaped mold containing expandable polystyrene (EPS). The EPS expands under the application of heat to fill the mold, thus creating a single panel's core. Once the core is removed from the mold, flat reinforcing frame strips are adhered to the faces of the core and to each other in order to frame the core. As an alternative, Dickens proposes placing the reinforcing strips into the mold prior to heating the EPS chips such that the polystyrene is expanded to fill the frame during expansion. U.S. Pat. No. 4,953,334 also to Dickens discloses an improved panel wherein the reinforcing strips include bent-over edges. When the EPS is expanded in the mold, the bent-over edges extend into the insulated core to provide increased panel stiffening.
While Dickens' method is sufficient for creating frame-type composite panels, the length of the panels produced is inherently restricted to the size of the core mold. However, as mold length is increased in order to create larger panels, it becomes increasingly difficult to uniformly regulate the application of EPS-expanding heat. As a result, the final product of such a process can suffer from inconsistencies.
Machine Development International (MDI) of Australia manufactures specialized systems for creating laminated composite panels of customs lengths. MDI's systems create laminated panels by forming individual core slabs, joining them end-to-end, and then applying the sheets of laminate end-to-end above and below the joined core slabs using an adhesive. The laminated structure is then cut into individual panels.
While MDI's systems can produce laminated composite panels of custom lengths, there is no known method of producing frame composite panels of the improved sort in Dickens' '334 patent, of lengths larger than a mold.
It is therefore an object of an aspect of the invention to provide a novel method of forming frame-type composite building panels.